[SOLVED] [AO_ALSA] Write error: Broken pipe

in this case it was a .mp4-file. the music frequently pauses (because of the error) until mplayercrashes after ~20min. the strange thing is that its happening with myonboard-chip and my external soundcard (NI Audio 2) and alsamixer shows Pulseaudio and if i switch the devices to HDA Intel w/ Conexant ID 5051 up .